Solved: VirtualBox new disk space not available even after resize

Why making things so complicated?

Environment:

• Oracle VirtualBox
• Ubuntu Linux 22.04 Server (i.e. CLI only)

Problem:

• In VM I original have 15 GB HD, and extend it to 30GB, but in VM I still see 15GB.

Solve:

• First, make sure you are following this tutorial to add and extend your disk space.
• But the above tutorial is not completed.
• You also need to read this post to get an idea on what is missing.
• But even if you read that, that post is not clear at all.
• So follow this:
• Run `lsblk` first to understand what you have
• 
  
  
• In my case, my ubuntu is installed in /dev/sda3, which "said" it has 30GB, but only 14GB is mount to /
• Run `vgs` to see more
• 
  
  
• 
  
• Start resize:
• First, run `pvresize /dev/sda3` to resize your partition
• Then you run `lvresize -L <SIZE>GB <VG_NAME>/<LV_NAME>` to resize volume group and LV_Name
• But how to find SIZE, VG_NAME and LV_NAME?
• SIZE = 30GB
• To find VG_NAME and LV_NAME, run `sudo lvdisplay`
• 
  
  
• Now you can complete this command, run 
• `sudo lvresize -L 30GB ubuntu-vg/ubuntu-lv`
• In my case, I tried different GB value, like 16GB, 28GB, 29GB
• In this answer, you can also use +5GB to increase space
• Now you need to resize your file system.  
• To get your file system, run `df -h`
• 
  
  
• Run `sudo resize2fs /dev/mapper/ubuntu--vg-ubuntu--lv`
• 
  
  
• Completed.  View your result: `df -h`
•